From Clark Howard - "the consumer warrior" website: http://www.clarkhoward.com/news/clar...ce-guide/nFbh/
Policies cost about 5% of total cost of a trip, but it's worth it. Consumers should always purchase a policy independent of the cruise, tour or vacation planner. Never purchase the trip protection plan from the trip organizer. They are designed to protect only the company and not the consumer. Always pay deposits and final payments by a real credit card and never by debit card or check.
You can comparison shop for trip insurance that suits your needs at http://www.insuremytrip.com/.

I never thought about the point of getting insurance from different provider - but makes sense. If the worst happens and they go out of business - not only is your trip ruined, but what chance do you have of getting money back.